1. Field of the Invention
The present invention relates to an intravenous flow controlling device which functions normally when solution is used up, abnormal solution dropping, drip chamber shaken, or drip chamber slanted.
2. Description of Related Art
Devices for controlling the flow of intravenous (IV) fluids to a patient are known. In general, they are designed to provide a constant fluid flow to patient and an automatic stop is activated once solution is used up for preventing air from injecting into patient. A conventional flow control device is shown in FIGS. 11A and 11B; As shown in FIG. 11A, the device is a float 2 having.a stud 2a underneath. Also, a hole c is provided on a divider for communication between upper and lower portions of drip chamber 1. In operation, float 2 is submerged as solution filled in drip chamber 1. As such, fluid may flow through exit b. The fluid level may drop as fluid exits. Float 2 may fall accordingly due to its weight. Finally, the stud 2a falls into hole c to stop the fluid flow through exit b.
However, the previous design suffered from a disadvantage. In detail, stud 2a may never fall into hole b when drip chamber 1 is shaken by an external force or slanted near the depletion of solution. This immediately causes stud 2a to contact the top of divider (i.e., top periphery of hole c) as shown in FIG. 11B. Now the float 2 is in a dead point. This also compromises the desired auto-stop functionality of the flow control device.
Another conventional flow control device is shown in FIGS. 12A to 12C. The device is a submerged reservoir 3 having a circular plane diaphragm d underneath. In operation, the submerged reservoir 3-is submerged as solution L filled in drip chamber 1. As such, fluid may flow through exit c. The fluid level drops as fluid exits. The submerged reservoir 3 full of solution L may fall accordingly due to its weight. Finally, the circular plane diaphragm d clogs exit c to stop the fluid flow when fluid in the drip chamber 1 is used up.
However, the previous design suffered from a disadvantage. In detail, a number of wrinkles dxe2x80x2 may be formed on the periphery of circular plane diaphragm d. As such, many channels s exist for communication with exit c as best illustrated in FIG. 12B. This means that circular plane diaphragm d is not completely adhered to the bottom of drip chamber 1 when solution L in the drip chamber 1 is used up. As such, fluid may pass the exit b through channels s. Further, a plurality of wings 3a (four are shown) are formed on the top periphery of submerged reservoir 3 being in contact with the inner wall of drip chamber 1 for stabilizing the up or down movement of float member 3. However, such design may only functions well when the submerged reservoir 3 has a cylindrical shape or the inner wall of drip chamber 1 is very smooth. Otherwise it may clog on the wall of drip chamber 1, thus compromising the floating functionality of submerged reservoir 3. The case shown in FIGS. 12A to 12C is not desirable since the drip chamber 1 has a concave spherical surface. In view of the above, the desired auto-stop functionality of this flow control device is also compromised.
It is thus an object of the present invention to provide an intravenous (IV) flow controlling device disposed in a drip chamber having an exit in the bottom. The device comprises a flexible float member having a specific gravity less than one and an outer diameter smaller than that of the drip chamber, the cup member including an upper portion and a spherical bottom portion thinner than the upper portion of the float member member; a first plastic tube coupled to the bottom of the float member being in communication with the exit of the drip chamber; a flexible reservoir having one end coupled to the first tube; and a second plastic tube coupled to the other end of the reservoir being in communication therewith, wherein the float member is submerged as fluid filled in the drip chamber, fluid flows through the exit of the drip chamber, the first plastic tube, the reservoir, and the second plastic tube to cause the float member to fall, thereby stopping fluid exiting when the bottom portion of the float member clogs the exit of the drip chamber and fluid in the drip chamber is used up, and the reservoir is capable of being squeezed to force solution stored in the reservoir to flow through the first tube in reverse direction to disengage the bottom portion of float member from the exit of the drip chamber. Therefore, the IV flow controlling device of the present invention still functions normally when solution is used up, abnormal solution dropping, drip chamber shaken, or drip chamber slanted.
It is another object of the present invention to provide an intravenous (IV) flow controlling device disposed in a drip chamber having an exit in the bottom. The device comprises a flexible float member having a specific gravity less than one and an outer diameter smaller than that of the drip chamber, the float member including an upper portion and a spherical bottom portion thinner than the upper portion of the float member member, wherein the float member is submerged as fluid filled in the drip chamber, fluid flows through the exit of the drip chamber to cause the float member to fall, thereby stopping fluid exiting when the bottom portion of the float member clogs the exit of the drip chamber and fluid in the drip chamber is used up. The IV flow controlling device of the present invention is still functioning normally when solution is used up, abnormal solution dropping, drip chamber shaken, or drip chamber slanted.
In one aspect of the invention, when an abnormal solution dropping such as excessive dripping of solution occurs due to carelessness of operator, the fluid level in the drip chamber is still maintained at a constant. Also, float member immediately falls a distance due to the sensitive design of the invention. Moreover, a strong suction force is formed at exit when float member falls to its lowest position, thereby causing the bottom of float member to clog exit to stop the fluid flow.